The first step in determining the nature of an unusual object in an image is to see what other images of the same area exist.

Here's yours, expanded to show more of the right side:

And here's a crop of http://www.nasa.gov/images/content/297717main_polar_AGU.jpg showing the same region:

Both images show the white wrapped cable bundle held to the top surface and routing over the edge. It's now apparent from the 297717 image that the "snake head" near the color calibration target is nothing more than a black wrapped cable bundle that is routed across the top deck and over the edge.

Always look for more images of the same area! More data is always better than less data.